The string quartet was a futuristic invention that didn't exist when J.S. Bach was alive. The piano trio wasn't much of a thing yet, either. But it's like Herr Bach knew they were coming.

As illustrated in this year's [email protected] program, the composer's stamp is everywhere, centuries after his day: on quartets, trios, concertos, preludes, fugues and even French music. This season, concerts and talks explore the question put forth by festival directors David Finckel and Wu Han: How did Bach's works influence so much of music yet to come? Or, as the two ask in a festival booklet, had "Bach's music, through its cosmic logic, simply opened our ears to hearing everything that followed it more clearly and vividly?"

The popular festival founded by cellist Finckel and pianist Wu Han is now in its 11th season. Running July 18 through Aug. 10, it's based at Menlo School in Atherton, with events at Stent Family Hall and Martin Family Hall on campus, and at the Center for Performing Arts over at Menlo-Atherton High School. Besides hosting concerts with big-name musicians, the festival also presents a lecture series and performances by musicians who are studying at the festival's Chamber Music Institute this summer.

Musicians new to the festival this year include the Danish String Quartet and violinist Soovin Kim; returning players include the Orion String Quartet, violinist Jorja Fleezanis, violist Arnaud Sussmann, pianist Gilbert Kalish and cellist Colin Carr.

This year's theme, "From Bach," is the focus of the eight mainstage concerts. The first, "Piano/Piano," looks at Bach's legacy as an organist and how it has inspired piano compositions by master composers in their own right: Schubert, Schumann, Bartok. It will be performed July 19.

On July 21 is "Quartet Dimensions." The Danish String Quartet and other players will explore Bach's influence on the quartet art form, including Mozart's string-quartet takes on Bach's "The Well-Tempered Clavier."

"String Variations," with performances on July 24 and 25, begins with Bach's "Brandenburg" Concerto No. 3 and continues the splendid-strings theme through pieces by Richard Strauss, Shostakovich and Mozart. Wu Han will be featured on harpsichord. On July 27, "Preludes and Fugues" looks at Bach's contrapuntal music and its influence on Haydn, Mendelssohn, Debussy, Gershwin, Britten and others.

Closing out the month is "Trio Transformations," on July 31 and Aug. 1. The program explores how Bach's sonatas led to the more modern piano-trio art form, featuring Jeffrey Kahane playing piano and harpsichord, Joseph Swensen playing violin and Carter Brey playing cello.

Bach's "French" Suites showed that the master went far beyond Germanic music, and the Aug. 2-3 program "French Connections" delves into the brightness and romance that later appeared in music by Saint-Saens, Debussy, Tournier and Franck.

On Aug. 6 and 7, many musicians will take on the master's final work, "Die Kunst der Fuge (The Art of Fugue)." Lastly, "The Solo Voice" looks at Bach's music for solo instruments, with his Concerto for Violin and Oboe in C minor, and pieces by Schubert, Mozart and Mendelssohn. Performance dates are Aug. 9 and 10.

Also at [email protected] are the Carte Blanche Concerts, which allow individual festival artists to curate their own recitals and single out pieces that have particular meaning to them.

Percussionists Christopher Froh, Ayano Kataoka and Ian Rosenbaum will be featured on July 20, followed by violinist Soovin Kim the next day. Colin Carr presents "Cello Evolutions I" on July 28; he performed all of Bach's cello suites at the festival in 2004 and will play two of them as part of the new program.

Violinist Jorja Fleezanis will be accompanied by soprano Elizabeth Futral and others in her "Into the Light" program on July 28, looking at how music gives voice to the human condition. Cellist Laurence Lesser follows on Aug. 4.

Meanwhile, classical-music scholars will be presenting "Encounter" lectures. The schedule is: "In the Beginning ... There Was Bach" with Ara Guzelimian on July 18; "Keyboard Evolution: How Bach's Instruments Became the Modern Piano" with Stuart Isacoff on July 26; "The Art of Late Bach: Exploring 'Musical Offering' and 'The Art of Fugue'" with Michael Parloff on Aug. 4; and "The Passion According to Sebastian Bach" with Patrick Castillo on Aug. 8.

Other talks and student-musician concerts, as well as master classes, will be held throughout the festival, with a [email protected] open house on July 20. Music-inspired paintings by Sebastian Spreng will be on exhibit.

Info: Tickets for mainstage concerts are $55-$77 ($20-$35 for those under 30), and Carte Blanche Concert tickets are $40-$75 ($20-$35 for those under 30). Encounter lectures are $45 general and $20 for the under-30s. Performances by musicians in the Chamber Music Institute are free. For a complete schedule and ticketing details, go to musicatmenlo.org or call 650-331-0202.